Net-based baffles for flexible intermediate bulk containers

ABSTRACT

A flexible intermediate bulk container (FIBC) for transferring various type of materials, including industry-based granule materials, fine materials like sugar, flour, comprising baffles sewed to edge region of the FIBCs for preventing bulging formation on lateral surfaces thereof so defining an essential volume and subsidiary volume in the FIBC and said baffles having holes for promoting material transfer between the essential volume and subsidiary volume the development comprising said baffle ( 3 ) formed as a net structure having plurality of filaments ( 4 ), plurality of net passages ( 10 ) between these filaments ( 4 ) and connection elements ( 8 ) the filaments ( 4 ) are attached thereon.

RELATED U.S. APPLICATIONS

This application is a continuation-in-part of application Ser. No. 10/134,664, filed Apr. 29, 2002.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

Not applicable.

REFERENCE TO MICROFICHE APPENDIX

Not applicable.

FIELD OF THE INVENTION

This invention relates to flexible intermediate bulk containers (FIBC) utilized for material transfer, particularly relates to net-based baffles for minimizing the space occupied by the FIBCs in the container while transferring thereof.

BACKGROUND OF THE INVENTION

Flexible intermediate bulk containers (FIBC) are extensively used for various bulk materials including industry-based granule, powder materials, food grade materials like sugar, flour, etc and even for quasi-fluid materials. Once the FIBCs are packed, they are accommodated into containers, trucks etc. for transferring thereof to another location.

Perhaps, one the most important aspects that is regarded as far as transferring the FIBCs are concerned is to achieve maximum amount of material transfer while minimizing the transfer sequence. This is the optimization problem leading the practitioners to minimize the space or volume occupied by the FIBCs in the container.

As a part of underlying physical effects, when bulk material, most of the time fine material, is introduced into an FIBC, it is tended (inclined) to move towards empty space or volume. It is interesting to note that, since edges of the FIBC are not available to promote such a tendency of bulk material movement, because of the physical restriction, the bulk material moves towards the lateral sides of the FIBC leading lateral bulged surfaces of the FIBC. Consequently, when the FIBCs are accommodated next to each other, simply some idle spaces are originated in the region of top and bottom corners of the FIBCs due to contact of the bulging surfaces of different FIBCs. However, these idle spaces occupy some considerable amount of volume, which is not filled by the material to be intended to transfer, in the container. The major requirement of a baffle is therefore to provide sufficient structural integrity so that bulging of the container sides is minimized and, at the same time, provide the maximum bulk material transmission through the baffle such that all of the spaces within the container are filled uniformly.

As a solution serving to overcome the above-mentioned problem in this technical field, numerous proposals have been made. Probably the most efficient proposals are focusing on sewing baffles to the edges of FIBCs diagonally. By doing so, movement tendency of bulk material towards the lateral sides of the FIBCs is decreased and potential bulging formation of the lateral sides is prevented.

The baffles accompanied with these solutions have hole-shaped formation and are sewed from the top region to the bottom region of the four edges of the FIBCs diagonally. The idea underlying the formation of these holes is to provide material penetration between the baffles and the edges in addition to essential part of the FIBCs.

It is acknowledged that the above-referenced solution put forwards sound advantages with respect to the deficiencies in the relevant technical field, however, another problems arise due to the physical nature of this solution such as interference of the baffle material to the bulk material carried due to spots of the holes. For instance, since the baffle is not a continuous part i.e. comprising holes, spots of the holes are likely to interfere with the bulk material. On the other hand, the present baffles are not able to be sewed through the edges i.e. from top to bottom, because of the idea that filling the space between the baffle and the edges of the FIBCs. In other words, in order to utilize the space between the sewed baffle and the edge, so providing bulk material transfer between the essential part and the space between the baffle and the edge, the baffle cannot be sewed through the edges i.e. through the top and bottom limits of the edges. As a consequence of this practice, the top and the bottom regions of the FIBCs become bulging driving indirectly volume loss in the container.

Another disadvantage accompanied with the state of the art is referred to structural deficiency in terms of functionality of the baffles. In fact for contributing the bulk material penetration through the holes of the baffles to the space between the baffle and the edge, a propeller is provided to promote uniform distribution of the bulk material in the FIBC. However, utilization of such a propeller induces many resources including labor, time.

It should also be noted that the normal method of fabricating baffles or similar structural maintenance means for a FIBC is to knit flaps to the side walls of the container and then to pass ropes through openings in the flaps. Thus, at least two separate process steps are required to anchor the baffles with the container. It would be advantageous if the baffles could be fixed to the container in a single step process.

BRIEF SUMMARY OF THE INVENTION

An object of the present invention is to provide substantially rectangular prism formation of the FIBCs so that the volume occupied thereof is minimized in the container. This is achieved by utilizing diagonally situated baffles which provide sufficient structural integrity to substantially eliminate bulging of the container sides and, at the same time, permit maximum bulk material transmission across the plane of the baffle to promote even filling of the central space and side spaces defined by the baffles and the container walls.

That object is achieved in part by forming the baffles of the present invention of filaments which are knitted. For purposes of this patent, the term “filament” is used to mean a single thread or a thin flexible thread-like object that has a substantially diametric geometry when viewed in cross-section. It is meant to exclude fabric strips or other long, narrow pieces of material.

Forming the baffles of the present invention of knitted filaments provides the necessary strength and promotes maximum material flow between the spaces which they define by reducing the surface area of the baffle to a minimum. The filaments, that is, a single thread or a thin flexible thread-like material, form the baffles which are sewed diagonally to the edges of the FIBCs through the top and bottom limits of the edges. Once the baffles are sewed to the edges, two volumetric regions or spaces are defined in the FIBC; one of these volumetric regions is referred to essential part in which most of the bulk material is held and the other volumetric region is referred as subsidiary part formed between the baffle and the edge of the FIBC.

The baffles of the present invention are formed of vertically extending elements and horizontally extending elements connected to the vertically extending elements. It is important that the elements which form the overall baffle be knitted together in the same production step, as explained in greater detail below. This means that the vertically extending elements are not produced with an independent production step and then the horizontally extending elements are attached to them in some manner, or visa versa. Further, the vertically extending elements are preferably composed of one or more threads and not a woven material.

The development introduced by the present invention is based upon net-based baffles promoting bulk material transition between the essential and subsidiary volumetric parts and simultaneously providing reducing movement tendency of bulk material towards the lateral surfaces of the FIBCs.

The net-based baffle in the scope of the present invention may be in a conventional fishing net or alternatively various net patterns. One significant technical feature proposed by this embodiment is that the plurality of passages and filaments providing structural integrity of the net. A second significant feature proposed by applicant's embodiment is that the baffles can be affixed to the container walls utilizing a single step method.

The requirement preventing a bulging formation of the FIBCs is that having a hexagon or octagon geometrical formation when viewed the FIBC from the top rather than having quadrangle once the baffles are sewed to the FIBCs, whereby bulk material movement tendency towards the lateral surfaces is reduced. In addition to this effect, the net-based baffles contribute to bulk material transition between the essential and subsidiary volumetric parts by means of the net structure.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

Further objects and advantages of the present invention will become apparent upon reading the following description taken in conjunction with the appended drawings wherein:

FIG. 1 illustrates a perspective view of a FIBC with net-based baffles sewed to the edges thereof;

FIG. 2 illustrates a top view of a FIBC with net-based baffles;

FIG. 3 a illustrates two column net-based baffles;

FIG. 3 b illustrates four column net-based baffles;

FIG. 4 a illustrates net-based baffle with triangle structure;

FIG. 4 b illustrates net-based baffle with diagonal structure;

FIG. 4 c illustrates net-based baffle with hexagonal structure;

FIG. 5 illustrates net-based baffle with quadrangle structure;

FIGS. 6 a and 6 b are respectively a front view of a typical baffle of the present invention and an enlarged section thereof showing the knitted structure thereof in detail;

FIGS. 7 a, 7 b and 7 c respectively illustrate the three types of threads that form the knitted structure of FIG. 6 b; and

FIG. 8 is a schematic representation of the machine used to form the knitted structure of FIG. 6 b.

DETAILED DESCRIPTION OF THE INVENTION

In FIG. 1, net-based baffles and the location thereof in the FIBC are illustrated. Conventionally, a FIBC, flexible intermediate bulk container (1) is a means for transferring materials and having a rectangular prism geometry carried by holders (2). The baffles (3) are sewed to the connection edges (9) of the FIBC (1) diagonally so as to obtain a relatively rounded geometry in the essential volume (11) of the FIBC, i.e. independent of sharp geometry due to edges. The lateral surfaces (7) are attached to each other by connection edges (9) so that the FIBC (1) is formed.

Net-based baffles (3) comprise preferably two vertically extending strips (8) and horizontally extending elements provided between the vertically extending strips, and net filaments (4). One of the vertically extending strips (8) is sewed to the lateral surface (7) and the inner one is embodied for connecting the net filaments (4) thereto. As an alternative structure, the vertically extending strips (8) of different baffles (3) may be sewed as one on the top of the other to the lateral surfaces (7).

As it is proposed, the net-based baffles (3) comprise plurality of net passages (10) providing bulk material transition between the essential volume (11) and the subsidiary volume (12). Furthermore, the net-based baffles (3) are sewed through the top limit (5) and bottom limit (6) of the FIBC (1). Whereby, potential bulging formation in the top and bottom regions is prevented.

In FIG. 2, top view of a FIBC with sewed net-based baffles (3) is illustrated. As seen in the figure, the essential volume (11) gains a rounded and compact geometry. In other words, once the net-based baffles (3) are sewed to the edges, the essential volume (11) become more rounded shape by hexagon or octagon geometries with respect to an essential part lacking baffles.

A preferred embodiment of the present invention is based upon an octagonal geometry when viewed from the top, however it may be possible to have a FIBC structure based upon a hexagonal geometry when baffles (3) are connected on a lateral surface (7).

In FIG. 3 a, an alternative baffle (3) with double column is illustrated. As seen in the figure, there is an intermediate connection (13) between the columns. Similarly, various embodiments can be derived as seen in FIG. 3 b showing an baffle (3) with quartet columns. The number of columns and intermediate connections (13) can be enhanced optionally. For baffles (3) having plurality of columns, the net filaments (4) are fixed from one end to the vertically extending strips (8) and connected to intermediate connections (13) from the other ends.

In FIG. 4 a, an alternative structure having triangle shaped net passages (10) is illustrated. As mentioned above, similarly, the number of columns can be increased optionally.

Similarly, in FIG. 4 b, an alternative structure having diagonal shaped net passages (10) is illustrated.

FIG. 4 c illustrates net passages (10) having hexagonal shaped formation.

In FIG. 5, quadrangle shaped net passages (10) are shown.

In the preferred embodiment, the space occupied by the horizontally extending threads of the baffle is about 3-20% in each one meter of baffle length. In other words, the area occupied by the threads connecting the vertically extending elements is about 3-20% of the rectangular area defined by the baffle, for each one meter of baffle length. In the most preferred embodiment, the space occupied by the horizontally extending threads is approximately 7% of each one meter of baffle length. In conventional baffles, this ratio is in the order of 70%, ten times that of the present invention. Furthermore, the thickness of those threads is preferably 0.5-5 nm.

The method of forming the net-based baffles of the present invention is illustrated in FIGS. 6 through 8.

The baffle is a knitted structure formed of three types of elements, each element being a filament, that are knitted together is a single operation by the machine illustrated in FIG. 8. FIG. 6 b illustrates in detail the structure that results from knitting the three types of elements, designated as first type, second type and third type, respectively. The first type element and the second type element are knitted to extend vertically. The third type element is knitted to extend horizontally to connect the first type and the second type.

FIGS. 7 a, 7 b and 7 c show the elements separately for clarity. FIG. 7 a shows the horizontally extending third type element. FIG. 7 b shows the first type vertically extending element and FIG. 7 c shows the second type vertically extending element.

In the preferred embodiment, the first type of element is formed of thread that is 1900 dtex (thread “gram” weight in each 10,000 “meter”), the second type element is formed of thread of 1100 dtex and the third type element is formed of thread of 3000 dtex. However, different relative and absolute thread gram weights may be utilized.

The vertically extending elements are formed by the side knots (first type) and by the side knot connecting threads (second type). As seen in the FIG. 8, the thread bobbins of the knitting machine are first arranged to a creel and threaded in to the machine. Knitting is performed by knitting heads being swinging and the knitting heads having needles at the tips thereof. Driving motion of the knitting heads is controlled by a computer programmed to form the baffle.

Three knitting heads are required to form the baffle of the present invention. Since there are six heads mounted on the machine, two baffles can be formed simultaneously.

Once the threads in the creel are threaded into the machine, the operator drives the machine to start the knitting process and the machine continuously knits the vertically extending elements and the connecting horizontal extending element. The knitted baffle is drawn by drums arranged to the machine. Although it is theoretically possible to continue knitting to form a baffle of any length, as a practical matter, the baffle is cut to a predetermined length size based upon the height of the container by the cutting and winding machine.

This baffle production method utilizes only threads as an input and only a single knitting machine is required to form the baffle. No manual intervention or additional devices are required. The baffle produced in this manner are directly sewn to the flexible containers.

One of the most important advantages of producing the baffles in a single (structurally integrated) process is to prevent baffle material involvement into bulk material which is most of the time food-based or chemical-based fine material or granule material. By way of contrast, baffles produced by discrete processes have a potential risk to be torn and contaminate the bulk material due to bulk material charging or discharging load.

Although only a limited number of preferred embodiments of the present invention have been disclosed for purposes of illustration, it is obvious that many variations and modifications could be made thereto. It is intended to cover all of those variations and modifications which fall within the scope of the present invention, as set forth in the following claims: 

13. A flexible intermediate bulk container (FIBC) for transferring various types of granule materials, said container comprising walls and baffles for preventing bulging of said container walls, said baffles comprising first and second vertically extending elements, and a horizontally extending element connecting said first and second vertically extending elements, said elements being knitted together, and means for connecting said baffles between said walls of the container, wherein each of said elements comprises a filament.
 14. The container of claim 13 wherein the space occupied by the horizontally extending element is about 3-20% of the rectangular area defined by said baffle, for each meter of baffle length.
 15. The container of claim 13 wherein the space occupied by the horizontally extending element is about 7% of the rectangular area defined by said baffle, for each meter of baffle length.
 16. The container of claim 13 wherein the thickness of the filament that comprises said horizontal element is within the range of 0.5-5 mm.
 17. The container of claim 13 wherein the gram weight for each 10,000 meters of the filament that comprises said first vertically extending element is approximately 1900 dtex.
 18. The container of claim 13 wherein the gram weight for each 10,000 meters of the filament that comprises said second vertically extending element is approximately 1100 dtex.
 19. The container of claim 13 wherein the gram weight for each 10,000 meters of the filament that comprises said horizontally extending element is approximately 3000 dtex.
 20. A method for fabricating a baffle for preventing bulging of the walls of a flexible intermediate bulk container (FIBC) of the type used for transferring various types of granule materials, the baffle comprising first and second vertically extending elements, and a horizontally extending element connecting said first and second vertically extending elements, the method comprising the steps of forming the first vertically extending element from a filament, forming the second vertically extending element from a filament, forming the horizontal extending element from a filament and knitting the first vertically extending element, the second vertically extending element and the horizontally extending element together in the same production step.
 21. The method of claim 20 wherein the step of knitting comprises knitting the elements together such that the space occupied by the horizontally extending element is about 3-20% of the rectangular area defined by the baffle, for each meter of baffle length.
 22. The method of claim 20 wherein the step of knitting comprises the step of knitting the elements together such that the space occupied by the horizontally extending element is about 7% of the rectangular area defined by said baffle, for each meter of baffle length.
 23. The method of claim 20 wherein the step of forming the horizontal element comprises the step of forming the horizontal element of a filament with a thickness within the range of 0.5-5 mm.
 24. The method of claim 20 wherein the step of forming the first vertically extending element comprises the step of forming the first vertically extending element of a filament with a gram weight for each 10,000 meters of the filament of approximately 1900 dtex.
 25. The method of claim 20 wherein the step of forming the second vertically extending element comprises the step of forming the second vertically extending element of a filament with a gram weight for each 10,000 meters of the filament of approximately 1100 dtex.
 26. The method of claim 20 wherein the step of forming the horizontally extending element comprises the step of forming the horizontally extending element of a filament with a gram weight for each 10,000 meters of the filament of approximately 3000 dtex. 